The present invention relates to a brake ring/hub connection via clamping notches for rail vehicles, with the hub having at least three clamping notches that extend radially between clamping arms, with the clamping or connecting strips that are disposed on the brake ring being pressed into the clamping notches and the hub being pressed onto an axle.
A connection of the brake ring and hub or shaft of this type was first proposed in German Patent 1 222 962 and was accepted worldwide, since it had a number of important advantages. A primary advantage of this connection was that despite the strong clamping of the connecting strips in the clamping notch, a radial expansion of the brake ring resulting from heating-up of the brake is possible because the connecting strip can migrate in the clamping notch without dangerous stresses occurring that would result in a loosening of the clamping connection.
However, since the stresses in the railroad traffic became increasingly greater, because the rail vehicles had to drive on poor tracks and/or were driven at higher speeds, the clamping force on the one hand and the strength of the clamping arms on the other hand were made so great (see the massive construction shown in FIGS. 1-3) that neither a lifting of the connecting strips on the back side (as seen in the direction of rotation), nor a plastic bending or turning up of the clamping arm of the notch that is in contact with the connecting strip resulted. This therefore led to German Patent 27 42 468, according to which, via a specific shape (see the overall view of FIG. 1) of the clamping notch and hardening of the inner surface of the notch, a rapid wearing of the clamping surfaces is prevented, and when the connecting strips are pressed into the clamping notch, in the region of the semicylindrical bottom surface of the clamping notch stresses having a uniform nature are formed, resulting in a greater clamping force at the clamping surfaces. The hardened volume of material, which results from the semicylindrical base surface of the clamping notch and the depth of the hardened layer and is provided with residual compressive stresses, serves to absorb the brake operation stress, whereby relative to this stress a greater strength of the clamping connection results than with the aforementioned construction pursuant to German Patent 1 222 962.
In the meantime, the stresses and demands on brakes and the travel mechanism have again increased considerably. As a result, the clamping connections between the brake ring and hub are increasingly stressed more greatly. In this connection, the clamping force on the one hand and the strength of the arms of the clamping connection on the other hand must be great enough relative to the forces that are applied that neither a lifting of the guide or connecting strips on the back side, nor a plastic bending of the notch arm that is in contact with the strip, occurs. The loads caused by the aforementioned stresses involve equivalent forces that, for example, result from the vertical accelerations that act upon the clamping connections. If the strength of the clamping connections is less than these forces, the clamping force is lost and the brake rings are loosened from the hub in the direction of rotation. Even if this does not result in a loss of the safety of the vehicle during braking because the brake disk is still functional, nonetheless this condition must be avoided so that further use of these brakes does not cause undue damage to the brake system. Unfortunately, the dimensions and relationships between the various parts of the hub of the aforementioned German patent 27 42 468 were not able to meet the latest stresses and demands.
It is therefore an object of the present invention to avoid the drawbacks of the heretofore used brake disks, and to provide a connection between the brake ring and hub that can also withstand the increased requirements of modern traffic and above all can also avoid the relatively high stresses from vertical accelerations.